Rinse solution for organs and tissues

The present invention was made with Government support under Grant Number DK37034 from the National Institutes of Health. The Government has certain rights to this invention.

This application is a continuation of U.S. application Ser. No. 08/105,602, filed Aug. 12, 1993, and now abandoned.

This invention relates to organ transplant rinse solutions in general, and particularly relates to organ transplant rinse solutions which contain glycine.

The introduction of cyclosporine for immunosuppression during the 1980's revived interest in transplanting organs and tissues, specifically, the liver, pancreas, heart, lung and heart-lung. However, preservation methods that are successful for kidneys have proved unsuccessful for these other organs. Until recently, the clinical preservation of the heart, liver and pancreas was kept to a minimum and to no longer than six to ten hours. Extending preservation time for these organs would have the same impact on their transplantation as it did on kidney transplantation, namely, increasing organ availability, decreasing organ wastage, increasing organ sharing, and reducing costs.

Organ transplant injury is believed to arise from two distinct components: damage induced during storage and damage resulting from reperfusion. See, e.g., G. Den Butter et al., Transplant. Proc. 25, 1633 (1993). Consistent with these two distinct sources of injury, two distinct types of solutions are available to extend the preservation time of organs: organ preservation solutions and organ rinse solutions.

Organ preservation solutions are used to store organs prior to transplant. An example of such a preservation solution, sometimes referred to as "University of Wisconsin" solution, is disclosed in U.S. Pat. No. 4,879,283 (see also U.S. Pat. No. 4,873,230) (available from E.I. du Pont de Nemours and Co. under the trademark VIASPAN™). Note that G. den Butter et al., supra, working with University of Wisconsin solution, conclude that glycine is protective in organ preservation and transplantation only when given to the recipient.

Organ transplant rinse solutions provide a useful compliment to organ preservation solutions. U.S. Pat. No. 5,145,771 to Lemasters and Thurman describes a solution for rinsing other preservation and storage solutions from an organ prior to implantation. This solution, referred to as "Carolina Rinse," comprises, in one liter of solution, from about 0.12 to about 1.2 mM adenosine; monosaccharide, sodium, potassium, calcium and magnesium ions; water for injection sufficient to make a liter of solution; with the solution having a pH of about 6.0 to 7.5 and a concentration of potassium of less than 6 MEQ/L.

An object of the present invention is to provide organ transplant rinse solutions with enhanced effectiveness, along with methods of using the same.

A first aspect of the present invention is an organ transplant rinse solution. The solution comprises, in one liter of solution, from 2 mM to 50 mM glycine, from 0.12 to 1.2 mM adenosine, monosaccharide, sodium, potassium, calcium and magnesium ions, and water for injection sufficient to make a liter of solution. The solution has a pH of about 6.0 to 7.5 and a concentration of potassium of less than 6 MEQ/L. The combination of these ingredients provide unique synergistic properties, as discussed in greater detail below.

A second aspect of the present invention is a solution for the rinsing of organs intended for implantation in a patient requiring such implantation prior to implantation. The solution comprises:

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NaCl 85 to 145 mM

KCl 3 to 6 mM

CaCl.sub.2 1.0 to 1.6 mM

KH.sub.2 PO.sub.4

0.7 to 1.3 mM

Glycine 2.0 to 50.0 mM

Adenosine 0.12 to 1.2 mM

Distilled deionized water

q.s.

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The solution has a pH of 6.0 to 7.4.

A third aspect of the present invention is a method of rinsing preservation or storage solution from organs or tissues intended for implantation in a patient requiring such implantation. The method comprises rinsing the organ or tissue prior (preferably immediately prior) to implantation with a rinse solution as described above. The rinse step may be preceeded by the step of maintaining the organ or tissue in a preservation or storage solution.

A further aspect of the present invention is a method of combating tissue reperfusion injury by rinsing preservation or storage solution from organs or tissues intended for implantation in a patient requiring such implantation. The method comprises rinsing the organ or tissue prior (preferably immediately prior) to implantation with a rinse solution as described above for a time and in an amount effective to combat tissue reperfusion injury. The rinse step may be preceeded by the step of maintaining the organ or tissue in a preservation or storage solution.

A still further aspect of the present invention is the use of the constituents of the solutions described above for the preparation of the rinse solutions described above.

The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth hereinbelow.

Suitable organs and tissues for carrying out the present invention include, but are not limited to, liver, pancreas, kidney, lung, heart, heart valves, arteries and veins, vascular segments, ligaments and tendons, and cellular components from liver, pancreas, blood and bone marrow. Suitable recipients for practicing the invention include mammalian recipients, including both human and animal (e.g., dog, cat, horse) recipients.

The rinse solution described herein is intended for use in rinsing the preservation or storage solution from the organ or tissue prior to implantation. It can optionally be used as a preservation or storage solution, and can be used at all temperatures, from about 0° C. to normal body temperature, 37° C. Likewise, the solution may be used for perfusing tissue in situ, for example, ischemic brain, heart, limbs or bowel, namely, an organ or tissue whose circulation is blocked by a blood clot.

By rinsing the organ or tissue with the solution prior to blood reperfusion, reperfusion injury can be prevented or minimized. Rinsing may be carried out by any suitable means which brings the rinse solution in contact with the organ or tissue in place of the preservation solution, including immersion and perfusion. In general, when used as a rinse solution for combatting reperfusion injury, the solution is substantially or essentially free of oxygen (i.e., no special steps are taken to elevate the oxygen content of, or oxygenate, the solution prior to contacting the solution to the organ or tissue). Where a storage solution is employed prior to the rinsing step, any storage solution may be employed, such as those described in U.S. Pat. Nos. 4,879,283 and 4,873,230 (the disclosures of which are incorporated by reference herein in their entirety).

The potassium concentration of the described rinse solution is maintained at a physiological level, less than about six millieguivalents per liter. It is desirable that a rinse solution not have a high potassium concentration. The solution is generally sterile and essentially pyrogen-free, as will be appreciated by those skilled in the art.

Rinse solutions of the present invention may be prepared as described in U.S. Pat. No. 5,145,771 to Lemasters and Thurman (the disclosure of which is to be incorporated by reference herein in its entirety), with the formulation described therein modified to include from 2 mM to 50 mM glycine. As one embodiment of the described invention, the rinse solution contains glycine as noted above, about 3 mM glutathione, 1 mM adenosine, 10 mM glucose, and sodium, potassium, calcium and magnesium ions, and a pH of 6.5. 2 μM of a calcium blocking agent such as nicardipene can be added. Other suitable blocking agents are nifedipine, diltiazem or verapamil. Fructose can replace the glucose. Ribose and adenine, together, can replace the adenosine. Preferably, the solution also contains about 5% hydroxyethyl starch, as described hereinafter.

A suitable colloid is a modified hydroxyethyl starch having a weight average molecular weight of about 50,000 to one million daltons. A preferred hydroxyethyl starch is one having a molecular weight of from about 150,000 to about 350,000 daltons and degree of substitution of from about 0.4 to about 0.7. A more preferred colloid is hydroxyethyl starch having a weight average molecular weight of from about 200,000 to about 300,000 daltons. The preferred colloid is substantially free of hydroxyethyl starch having a molecular weight of less than about 50,000 daltons. In accordance with one embodiment of the present invention, the hydroxyethyl starch is dialyzed against distilled-deionized water or otherwise treated to remove contaminants which have an adverse affect on the effectiveness of hydroxyethyl starch preparations. The materials removed by the dialysis process are the very smallest hydroxyethyl starch components, including the ethylene glycol and ethylene chlorohydrin side products of the hydroxyethylation as well as the residual acetone and sodium chloride. Other suitable, but less preferred, colloids are albumin, dextran, polyethylene glycol and polyvinyl pyrolidone.

In a preferred embodiment, the rinse or preservation solution composition includes, but is not limited to, the components in about the concentration ranges set forth in Table 1 below. As noted above, the hydroxyethyl starch is optional but preferred.

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Concentration Ranqes in 1 Liter

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10% modified hydroxyethyl starch

30 g/L to 100 g/L

NaCl 85 mm to 145 mM

KCl 3 mM to 6 mM

CaCl.sub.2 1.0 mM to 1.6 mM

KH.sub.2 PO.sub.4 0.7 mM to 1.3 mM

MgSO.sub.4 0.9 mM to 1.5 mM

Allopurinol 0.05 mM to 5 mM

Desferrioxamine 0.02 mM to 2.0 mM

Glutathione 0.5 mM to 10.0 mM

Nicardipene 0.1 μM to 5 μM

Adenosine 0.1 mM to 5 mM

Glycine 2 mM to 50 mM

Fructose 1 mM to 50 mM

Glucose 1 mM to 50 mM

Insulin 5 U/L to 250 U/L

Mops 2 mM to 40 mM

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The following examples are intended to be illustrative of the present invention but should not be considered as limiting the scope thereof.